NPR — along with seven public radio stations around the country — is chronicling the lives of America's troops where they live. We're calling the project "Back at Base," and this is the second installment of the ongoing series.

It was 2005, and Gary Walters had served a year in Iraq. Then, one day, a bomb went off near him, and he suffered severe wounds.

He ended up at Brooke Army Medical Center in San Antonio, where his right leg was amputated.

He was fitted for a prosthesis — an artificial leg below the knee.

He's lived with it for years, but it's not perfect.

"I was cutting my grass last summer, and trying to think of something to do, I'm like, 'You know what, this heat buildup in the prosthetics, it's an issue for everybody,' " Walters says.

As good as prosthetics are these days, they're still limited. Research is underway to help people navigate a turn more easily, or to keep the leg from rolling to the side. And then there's the problem Walters endures — they get hot.

"What they make prosthetics out of doesn't release heat," he says. "It gets really hot, you start to sweat a lot, and then the sweat can't go anywhere. On a good August day in San Antonio, I can build up an inch of sweat in the bottom of my prosthetic."

That sweat can cause a series of other problems like blisters and skin infections that can make wearing the prosthetic so painful that people stop wearing them.

So while studying to be an engineer, Walters designed a cooling fan. His idea won a $100,000 grant allowing him to continue his research. He teamed up to form a company, called Leto Solutions, to sell the product on a larger scale.

"It is a problem that the VA, that the Department of Defense has recognized," says Becky Ariana, president and CEO of Leto Solutions. "But to date, there is no solution to really solving the problem of heat."

Ariana's working through a long to-do list. The first step is to figure out the right customers for this new prosthetic.

"Our initial target audience will be the federal space that includes the three DoD institutions — the Center for the Intrepid, Balboa Naval Medical Center out in San Diego, and Walter Reed in Washington, D.C," she says.

At the Center for the Intrepid in San Antonio, prosthesis are housed on a floor-to-ceiling shelf.

"This is our outgoing rack," says John Fergason, head of the prosthetics lab at the Center for the Intrepid. "When stuff comes here, I know to schedule the patients and get them in here and get everything fitted."

Fergason says there are almost as many types of devices as there are injuries, including an arm corner, an artificial shoulder joint, an electronic power-to-elbow, an electronic wrist and an electronic hand.

"What you have here is a running leg, so it's designed specifically for running," he says.

So the goal is to get Walters' idea for a self-cooling prosthetic onto that rack at the Center for the Intrepid.

Ariana has enough initial funding, and she has developed relationships with preferred federal vendors, which is a crucial step, according to financial analysts.

Next on her to-do list: A beta test.

"Collecting information about the performance of the product, the convenience of the product, how it changed the amputee's quality of life," Ariana says.

Fergason says one goal is to get devices into the civilian sector to help even more people.

But that won't be easy.

Brady Baker, an orthopedics analyst at Millennium Research Group, says insurers are scrutinizing prosthetic devices more closely than ever.

"So if it is going to be one of these high-priced lower extremity devices that is really undergoing a lot of scrutiny right now, I would say that has a lower likelihood of successfully penetrating the market," Baker says.

Artificial legs can cost anywhere from $6,000 to tens of thousands of dollars. It's one thing to come up with a way to make them better. It's another to get that good idea to market.

On this Veterans Day, we're launching a new project. NPR, along with eight public radio stations around the country, will chronicle the lives of America's troops and vets where they live. We're calling the project Back at Base. And today we look at an effort to create better prosthetics for the wounded. Modern prosthetics are high tech and made with advanced materials and elaborate electronic controls, but they're not perfect. Eileen Pace, of Texas Public Radio, has the story of one wounded vet who came up with an idea to improve his artificial leg. His challenge now - how to get that prosthetic built so that it can help others.

EILEEN PACE, BYLINE: Gary Walters had served a year in Iraq. It was 2005, and then one day, a bomb went off near him. He suffered severe wounds. He ended up at Brooke Army Medical Center in San Antonio, where his right leg was amputated. Walters was fitted for a prosthesis - an artificial leg below the knee. He's lived with it for years, but it's got its flaws.

GARY WALTERS: I was cutting my grass last summer and trying to think of something to do. I'm like, you know what? This heat build-up in the prosthetics is - it's an issue for everybody.

PACE: As good as prosthetics are, they're still limited. There's research underway now to help people navigate a turn more easily or to keep the foot stable in all positions. And then there's the problem that Gary Walters endures - they get hot.

WALTERS: What they make prosthetics out of doesn't release heat. You start to sweat a lot, and then the sweat can't go anywhere. So on a good August day in San Antonio, I can build up an inch of sweat in the bottom of my prosthetic.

PACE: So Walters, while studying to be an engineer, designed a cooling fan. His idea won a $100,000 grant, allowing him to continue his research. He teamed up to form a company to sell the product on a larger scale. Becky Ariana is president and CEO of the company - Leto Solutions.

BECKY ARIANA: It is a problem that the VA, that the Department of

Defense, has recognized. But to date, there is no solution to really solving the problem of heat.

PACE: Ariana's working through a long to-do list. First thing - figure out the right customers for this new prosthetic.

ARIANA: Our initial target audience will be the federal space. That includes the three DOD institutions - the Center for the Intrepid, Balboa Naval Medical Center out in San Diego and Walter Reed in Washington, D.C.

JOHN FERGUSON: This is our outgoing rack. When stuff comes here, I know to schedule the patients and get them in here and get everything fitted.

PACE: That's John Ferguson. He's chief of prosthetics at the Center for the Intrepid in San Antonio. And that rack he's pointing to is filled, floor to ceiling, with prosthetic arms and hands and legs.

FERGUSON: What you have here is a running leg. So it's designed specifically for running.

PACE: He says there are almost as many types of devices as there are injuries.

FERGUSON: Here's an arm corner, all right. So there's an artificial shoulder joint, an electronic power-to-elbow, an electronic wrist and an electronic hand.

PACE: So the goal is to get Gary Walters' idea for a self-cooling prosthetic onto that rack at the Center for the Intrepid. CEO Becky Ariana has enough initial funding, and she's developed relationships with preferred federal vendors - a crucial step, according to financial analysts. Next on her to-do list - a beta test.

ARIANA: Collecting information about the performance of the product, the convenience of the product, how it changed the amputee's quality-of-life.

PACE: John Ferguson, at the Center for the Intrepid, says one goal is to get devices into the civilian sector to help even more people, but that won't be easy. Brady Baker is an orthopedics analyst at Millennium Research Group. He says insurers are scrutinizing prosthetic devices now more closely than ever.

BRADY BAKER: So if it is going to be one of these high-priced lower extremity devices that is really undergoing a lot of scrutiny right now, I would say that has a lower likelihood of successfully penetrating the market.

PACE: Artificial legs can cost anywhere from $6,000 to tens of thousands of dollars. It's one thing to come up with a way to make them better. It's another to get that good idea to market. For NPR News, I'm Eileen Pace in San Antonio. Transcript provided by NPR, Copyright NPR.